Cannon-pinion for watches



(No Model.)

L. C. BRIGGS.

CANNON PINION FOR WATCHES. No. 388,625. Patented Aug. 28, 1888.

w ill! II II Attorney UNITED STATES PATENT OFFICE.

LEONARD G. BRIGGS, OF EAST SAGINAV, MICHIGAN.

CANNON-PINION FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 388,625, dated August28, 1888.

(No model.)

To all whom it may concern.-

Be it known that I, LEONARD O. BRIGGS, of East Saginaw, Saginaw county,and State of Michigan, a citizen of the United States, have inventedcertain new and useful Improvements in Cannon-Pinions; andI declarethefollowing to be a full, clear, and exact description of the same,suchas will enable othersskilled in the art to which it appertains to makeand use the same, reference being had to the accompanying drawings,which form a part of this specifieation.

In the said drawings, Figure 1 is a view in elevation of a cannoupinionembodying my invention. Fig. 2 is a sectional view of the same. Fig. 3is aside elevation of the journal for the pinion. Fig. 4 is an invertedplan. Fig. 5 represents the pinion in use. Fig. 6 is an enlargedsectional view illustrating the pinion upon its journal.

Heretofore in the construction of cannonpinions various means have beendevised for confining the pinion uponitsjournal. To this end the hub ofthe pinion upon its lower side has been split and provided with adovetailed recess in the bore of the pinion, nearits lower end, adaptedto set down over a sharp dovetailed shoulder on the journal. This,however, has required that the pinion be spread at the lower end of thehub by a screw driver or other tool, so as to spring it out over thisabrupt dovetailed shoulder. This results hequently in so springing thematerial of the hub that it will set and not return to its properposition, and so not hug closely upon the journal. Such a conditiondestroys the utility of the cannon-pinion, and if it cannot be sprungback it is rendered useless. Again, the arbor end of the pinion has alsobeen split and pro vided upon. its interior with an annular dovetailedrecess adapted to be sprung over a corresponding dovetailed projectionon the sur faceof thejournal. This,however,has proved a source ofconsiderable annoyance, for not only is the split portion liable tobecome set by putting it over the said shoulder, but this being thearbor, the slightest spring prevents the ready adjustment of the handsupon the arbor. In both the cases above cited it is an expensive anddifficult matter to turn a groove upon the interior of the hub of thecannonpinion, either at its lower end or at its arbor end.

It is the purpose of my invention to produce a construction which is atonce simple and efficacious, and is in no way liable to injure the saidpinion, and is so inexpensive in its construction as to add little ornothing to the expense.

To this end, A represents a cannon-pinion; B, its journal. I split thehub of the cannonpinion on its under side, as shown at a, and eitherbefore or after splitting the huh produce the annular indentation a atthe lower end of the bore of the hub. By thus indenting the metal themetal itself is upset, so as to throw in a slight burr or tlange, a",into the in terior of the bore. The journal B is of the usual uniformdimensions from top to base of the pinionseat; but at the base of thepinionseat I turn a slight groove, I), and this is sloped or beveleddownward, substantially as shown. It is now apparent that no expandingoperation by a tool of any kind is necessary. On the other hand,thepinion is simply slipped down over the journal and its inwardlyturnedannular burr a springs into the groove 1); but this groove beingbeveled, as shown, the tendency is for the pinion to crowd itself snuglydownward against its scat. Now when it is desired to remove thiscannoupinion it is only necessary to give a slight pull with the hand,and off it comes without the use of any tool in either operation. Vhilethis is described solely in connection with a cannon pinion, it is ofcourse clearly applicable in any similar locality where a pinion of thischaracter is to be loosely journalcd in a fixed position upon a shaft,and I would have such use of my invention treated as an equivalent.

What I claim is- The combination, with ajonrnal, B, of uniformdimensions from top to base of the pinion-seat, with the exception of agroove, 1), of a pinion having at the lower end of its split hub anindentation, a,and an in wardlyt-urned flange or burr, substantially asdescribed.

LEONARD C. BRIGGS.

Witnesses:

D. V. LE VALLEY, JENNER E. Monsn.

